Thread brake

ABSTRACT

A drum brake ( 1 ) having a rotatably journalled drum ( 2 ) and means ( 3 ) for adjusting the torque of the drum ( 2 ) has several peripherally-extending take-up slots ( 4 ) for filaments ( 5 ) with the slots being spaced from each other in the direction of the drum axis (X).

The invention relates to a filament brake having a rotatably journalleddrum and means for adjusting the torque of the drum.

In spiraling arrangements for applying a spirally-shaped filament layer,for example onto a plastic or rubber hose as a reinforcement layer orfor textile machines, it is necessary to ensure a uniform filamenttension in a plurality of filaments which are each pulled off of afilament spool.

A filament brake for textile machines is known from DE 299 07 679 U1wherein an individual filament is at least partially wrapped around abearing-mounted brake roller which is rotatably journalled. To adjust adefined filament tension, the brake torque of the filament brake can beadjusted with an adjusting screw. An inherent filament brake is requiredper filament for a plurality of filaments. A uniform adjustment of thefilament tensions for the filaments cannot be ensured because eachfilament brake must be adjusted individually.

A bobbin creel is described in U.S. Pat. No. 2,093,206 wherein thefilaments, which are pulled off a filament spool, are guided directly toa first deflecting ring and from there to a second deflecting ring. Thetwo deflecting rings are displaceable with respect to each other in sucha manner that the filament tension can be adjusted. Since the filamentsof the filament spools are, however, not pulled off tangentially, thewrap-around angle changes continuously during the operation of thebobbin creel so that no uniform filament tension can be ensured.

It is therefore an object of the invention to provide a filament brakewherein a plurality of filaments can be adjusted to constant filamenttensions simultaneously with respect to each other by means of anactuating variable.

The object is solved in that a plurality of take-up slots are providedfor the filaments. These slots are spaced from each other in thedirection of the drum axis.

According to the invention, the tension of several filaments from acommon drum can be reduced or increased at the drum takeout relative tothe drum intake. The filaments are preferably wrapped around the drum anumber of times per take-up slot.

The torque of the drum or several drums is preferably synchronouslyadjusted by a common drive element, for example, a belt drive, chaindrive or a gear train.

Alternatively, a means for adjusting the torque can be provided for eachfilament brake, for example, a clutch/brake combination with an electricmotor.

The take-up slots have an arcuate shape when viewed in cross section.The diameter of the drum at the filament intake is greater than at thefilament run out. A filament wound several times in the take-up slot is,in this way, pushed from the filament intake to the filament run out sothat overwinding does not occur and a defined spring tension in the runout is built up.

The drum can be configured as a drum journalled at one end or as a shaftjournalled at both ends.

In an alternate embodiment, an ancillary shaft can be mounted borderingthe drum and inclined to the drum axis. The filaments each wrap aroundthe combination of drum and ancillary shaft so that a filament is guidedback from the drum via the ancillary shaft to the drum. The filament isdisplaced on the drum in the axial direction and an overwinding isprecluded because the ancillary shaft is mounted inclined to the drumaxis. In this way, the filaments are compelled to run out synchronouslyfrom the drum.

The invention will now be described in greater detail below with respectto the attached drawings.

FIG. 1 shows a perspective view of a filament brake of the invention;

FIG. 2 shows a perspective side view of a filament brake with a drumshaft journalled at both ends;

FIG. 3 is a side view of a drum having take-up slots which are profiledto have an arcuate form;

FIG. 4 shows a perspective view of a filament brake having an additionalshaft.

FIG. 1 shows a filament brake 1 in a perspective view. The filamentbrake essentially comprises a cylindrically-shaped drum 2 and a drivewheel 3 with means 3 for adjusting the torque. The means for adjustingthe torque can, for example, be a clutch/brake unit with an electricmotor. The following can be used as transfer elements: belts, chains orgear assemblies.

According to the invention, a plurality of take-up slots 4 are providedwhich extend about the outer periphery of the drum 2 and each isseparated from the other in the direction of the drum axis x. Thetake-up slots 4 run about the outer periphery of the drum 2. Onefilament 5 is taken up per take-up slot 4. The filament 5 is wrappedaround the drum 2 several times and is placed in the take-up slot 4. Inthis way, a filament 5 can be driven or braked by the filament brake 1.The filament tensions of all filaments 5 of a filament brake 1 areadjusted uniformly.

In the embodiment shown, the drum 2 is journalled at one end so that thefilaments 5 can be easily placed in the take-up slots 4.

FIG. 2 shows an embodiment of a filament brake 1. The drum 2 isconfigured as a drum shaft 6 journalled at both ends. A drive wheel 3 isdisposed at one end of the drum shaft 6 and this drive wheel 3 coactswith means 3 for adjusting the torque. The receiving slots 4 areprovided on the periphery of the drum shaft 6 again at a spacing fromeach other. The take-up slots 4 extend about the outer periphery of thedrum shaft 6.

FIG. 3 shows the drum 2 in a side view. The take-up slots 4 have anarcuately-shaped profile. The filament intake 7 of the filament 5 is inthe region of the larger diameter of the take-up slot 4 and the filamentrun out 8 is provided at the lower diameter so that the filament 5migrates axially with the rotation of the drum 2 in the direction of thesmaller diameter of the take-up slot 4. In this way, overwindings areavoided and a uniform filament tension develops.

FIG. 4 is another embodiment of the filament brake. An ancillary shaft 9is provided adjacent to the drum 2 and inclined to the drum axis X. Thefilaments 5 each wrap around the combination of the drum 2 and theancillary shaft 9 and are placed over both the drum 2 and the ancillaryshaft 9 as shown. Because of the ancillary shaft 9, which is arrangedinclined to the drum 2, the filaments 5 are placed axially on the drum 2so that, in turn, the filaments migrate axially from the filament intake7 to the filament run out 8. Overwindings are avoided and a unitaryfilament tension is formed.

1-7. (canceled)
 8. A filament brake comprising: a rotatably journalleddrum defining a drum axis (X); said drum having a plurality ofperipherally-extending take-up slots formed thereon for accommodating aplurality of filaments therein; said take-up slots being spaced one fromthe other in the direction of said drum axis (X); and, means foradjusting the torque of said drum.
 9. The filament brake of claim 8,wherein each of said slots has an arcuate shape viewed in cross sectionand includes a filament intake region and a filament run-out region;said drum having a first diameter at said intake region and a seconddiameter at said run-out region; and, said first diameter is greaterthan said second diameter.
 10. The filament brake of claim 8, whereinthe drum is journalled at one end.
 11. The filament brake of claim 8,wherein the drum is a shaft journalled at both ends.
 12. A filamentbrake comprising: a rotatably journalled drum defining a drum axis (X);said drum having a smooth surface; an ancillary shaft adjacent said drumand arranged inclined to said drum axis (X); and, a plurality offilaments being wrapped around the combination of said drum and saidancillary shaft.
 13. A spiraling arrangement comprising: a plurality offilament brakes; each of said filament brakes including: a rotatablyjournalled drum defining a drum axis (X); said drum having a pluralityof peripherally-extending take-up slots formed thereon for accommodatinga plurality of filaments therein; said take-up slots being spaced onefrom the other in the direction of said drum axis (X); means foradjusting the torque of said drum; and, said means including a motor orbrake device for generating said torque and transmitting said torque tosaid drum.
 14. The spiraling arrangement of claim 13, wherein saidplurality of filament brakes are synchronously controlled by a commondrive element.